One‐Pot Preparation of Methyl N ‐Phenyl Carbamate and Zn(OAc) 2 /SiO 2 Catalyst with Enhanced Stability

The one‐pot preparation of methyl N ‐phenyl carbamate (MPC) and supported Zn(OAc) 2 /SiO 2 ‐OP was investigated. Zn(OAc) 2 and SiO 2 were added to the reaction between dimethyl carbonate (DMC) and aniline upon which MPC and Zn(OAc) 2 /SiO 2 ‐OP were obtained simultaneously. The co‐prepared Zn(OAc) 2 /SiO 2 ‐OP showed superior catalytic performance for MPC synthesis, giving a aniline conversion of 96.3% and a MPC selectivity of 99.7%. Compared with catalyst prepared by incipient impregnation, Zn(OAc) 2 /SiO 2 ‐OP was more stable during the reaction, and the aniline conversion was 85.0% with MPC selectivity of 88.2% for the seventh time. The catalyst was characterized and the results suggested that Zn(OAc) 2 , Zn 5 (OH) 8 (OAc) 2 ⋅2H 2 O, ZnO and Zn 4 O(OAc) 6 are present on SiO 2 surface. Zn(OAc) 2 and Zn 4 O(OAc) 6 are the active sites for MPC synthesis. The superior stability of the Zn(OAc) 2 /SiO 2 ‐OP catalyst came from the presence of Zn 4 O(OAc) 6 .